Urbina, Susana, author
John Wiley & Sons, 2004
Buku Teks
Cronback, Lee J.
Harper International Student , 1964
Buku Teks
Cohen, Ronald Jay, author
Mayfield Publishing Company, 1999
Buku Teks
Groth-Marnat, Gary, author
John Wiley & Sons, 2003
Buku Teks
Groth-Marnat, Gary
John Wiley & Sons Inc., 1999
Buku Teks